Method for transmitting/receiving signal for wireless communication, and device therefor

ABSTRACT

A terminal having reduced capability so as to support a bandwidth smaller than a specific bandwidth, according to one embodiment of the present invention, can detect a physical broadcast channel (PBCH) signal through a synchronization signal block (SSB) on a first downlink (DL) bandwidth part (BWP), obtain a part of system information including a master information block (MIB) carried by the PBCH signal from among pieces of first system information provided on the first DL BWP, and obtain second system information provided on a second DL BWP that is different from the first DL BWP.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of International Application No.PCT/KR2021/006139, filed on May 17, 2021, which claims the benefit ofearlier filing date and right of priority to Korean Patent ApplicationNo. 10-2020-0058639, filed on May 15, 2020, the contents of all of whichare hereby incorporated by reference herein in their entireties.

TECHNICAL FIELD

The present disclosure relates to wireless communication, and moreparticularly, to a method of transmitting or receiving anuplink/downlink signal in a wireless communication system and apparatustherefor.

BACKGROUND ART

Generally, a wireless communication system is developing to diverselycover a wide range to provide such a communication service as an audiocommunication service, a data communication service and the like. Thewireless communication is a sort of a multiple access system capable ofsupporting communications with multiple users by sharing availablesystem resources (e.g., bandwidth, transmit power, etc.). For example,the multiple access system may be any of a code division multiple access(CDMA) system, a frequency division multiple access (FDMA) system, atime division multiple access (TDMA) system, an orthogonal frequencydivision multiple access (OFDMA) system, and a single carrier frequencydivision multiple access (SC-FDMA) system.

DISCLOSURE Technical Problem

The object of the present disclosure is to provide a method oftransmitting and receiving signals more efficiently in a wirelesscommunication system where different types of user equipments (UEs)operate.

The objects of present disclosure are not limited to what has beenparticularly described hereinabove, and other objects that the presentdisclosure could achieve will be more clearly understood from thefollowing detailed description.

Technical Solution

In an aspect of the present disclosure, there is provided a method ofreceiving a signal by a user equipment (UE) in a 3rd generationpartnership project (3GPP) based wireless communication system. Themethod may include: detecting a physical broadcast channel (PBCH) signalin a synchronization signal block (SSB) on a first downlink (DL)bandwidth part (BWP); obtaining partial system information including amaster information block (MIB) carried by the PBCH signal from amongfirst system information provided on the first DL BWP; and obtainingsecond system information provided on a second DL BWP different from thefirst DL BWP. Based on that the UE is a second type of UE with reducedcapability to support a smaller bandwidth than a first type of UE, theUE may be configured to: perform BWP switching from the first DL BWP tothe second DL BWP; and obtain the second system information provided onthe second DL BWP as remaining parts except for the partial systeminformation obtained on the first DL BWP.

The UE may be configured to perform cell access based on a plurality ofinitial DL BWPs.

The first DL BWP and the second DL BWP may be a first initial DL BWP anda second initial DL BWP, respectively.

The first DL BWP may be related to a bandwidth of the first type of UE,and the second DL BWP may be related to a bandwidth of the second typeof UE.

The PBCH signal on the first DL BWP may be a common signal for the firsttype of UE and the second type of UE.

The second system information may be information for the second type ofUE other than the first type of UE. The second system information mayinclude at least one second-type system information block (SIB) for thesecond type of UE.

Obtaining, by the UE, the partial system information on the first DL BWPmay include: obtaining a first control resource set (CORESET)configuration and a first common search space (CS S) configuration fromthe MIB, wherein the first CORESET configuration and the first CSSconfiguration may be related to control information schedulingfirst-type system information block 1 (SIB1) for the first type of UE;and obtaining the first-type SIB1 based on the first CORESETconfiguration and the first CSS configuration, and

Obtaining, by the UE, the second system information on the second DL BWPmay include obtaining at least one second-type SIB provided on thesecond DL BWP based on the first-type SIB1.

Obtaining, by the UE, the partial system information on the first DL BWPmay include obtaining a first CORESET configuration and a first CSSconfiguration from the MIB, wherein the first CORESET configuration andthe first CSS configuration may be related to control informationscheduling first-type SIB1 for the first type of UE.

Obtaining, by the UE, the second system information on the second DL BWPmay include: obtaining at least one of a second CORESET configuration ora second CSS configuration on the second DL BWP by applying atime/frequency offset to at least one of the first CORESET configurationor the first CSS configuration; and obtaining at least one second-typeSIB provided on the second DL BWP based on the at least one of thesecond CORESET configuration or the second CSS configuration.

In another aspect of the present disclosure, there is provided aprocessor-readable storage medium having stored thereon a program forexecuting the above-described method.

In another aspect of the present disclosure, there is provided a devicefor 3GPP based wireless communication. The device may include: a memoryconfigured to store instructions; and a processor configured to performoperations by executing the instructions. The operations performed bythe processor may include: detecting a PBCH signal in an SSB on a firstDL BWP; obtaining partial system information including an MIB carried bythe PBCH signal from among first system information provided on thefirst DL BWP; and obtaining second system information provided on asecond DL BWP different from the first DL BWP. Based on that the deviceis a second type of device with reduced capability to support a smallerbandwidth than a first type of device, the processor may be configuredto: perform BWP switching from the first DL BWP to the second DL BWP;and obtain the second system information provided on the second DL BWPas remaining parts except for the partial system information obtained onthe first DL BWP.

The device may further include a transceiver configured to transmit andreceive a radio signal under control of the processor.

The device may be a UE for the 3GPP based wireless communication.

The device may be an application-specific integrated circuit (ASIC) or adigital signal processing device.

In another aspect of the present disclosure, there is provided a methodof transmitting a signal by a base station in a 3GPP based wirelesscommunication system. The method may include: transmitting a PBCH signalin an SSB on a first DL BWP; and transmitting second system informationon a second DL BWP different from the first DL BWP. The base station maybe configured to: support both a first type of UE and a second type ofUE with reduced capability to support a smaller bandwidth than the firsttype of UE; provide partial system information including an MIB carriedby the PBCH signal to the second type of UE by transmitting first systeminformation on the first DL BWP; and provide remaining systeminformation to the second type of UE by transmitting the second systeminformation on the second DL BWP.

In a further aspect of the present disclosure, there is provided a basestation configured to transmit a signal in a 3GPP based wirelesscommunication system. The base station may include: a memory configuredto store instructions; and a processor configured to perform operationsby executing the instructions. The operations performed by the processormay include: transmitting a PBCH signal in an SSB on a first DL BWP; andtransmitting second system information on a second DL BWP different fromthe first DL BWP. The processor may be configured to: support both afirst type of UE and a second type of UE with reduced capability tosupport a smaller bandwidth than the first type of UE; provide partialsystem information including an MIB carried by the PBCH signal to thesecond type of UE by transmitting first system information on the firstDL BWP; and provide remaining system information to the second type ofUE by transmitting the second system information on the second DL BWP.

Advantageous Effects

According to an embodiment of the present disclosure, a user equipment(UE) with reduced bandwidth capability may perform initial downlink (DL)bandwidth part (BWP) operation and system information acquisition moreefficiently.

The effects of present disclosure are not limited to what has beenparticularly described hereinabove, and other effects that the presentdisclosure could achieve will be more clearly understood from thefollowing detailed description.

DESCRIPTION OF DRAWINGS

FIG. 1 illustrates physical channels used in a 3rd generationpartnership project (3GPP) system as an exemplary wireless communicationsystem, and a general signal transmission method using the same.

FIG. 2 illustrates a radio frame structure.

FIG. 3 illustrates a resource grid of a slot.

FIG. 4 illustrates a random access procedure.

FIG. 5 illustrates an example of physical channel mapping.

FIG. 6 illustrates an exemplary acknowledgment/negative acknowledgment(ACK/NACK) transmission process.

FIG. 7 illustrates an exemplary physical uplink shared channel (PUSCH)transmission process.

FIG. 8 illustrates an example of multiplexing control information in aPUSCH.

FIGS. 9 to 11 illustrate signal transmission and reception related toproposals of the present disclosure.

FIGS. 12 to 16 are diagrams for explaining initial DL BWP operation andsystem information reception related to the proposals of the presentdisclosure.

FIG. 17 illustrates signal transmission and reception related to theproposals of the present disclosure.

FIGS. 18 and 19 illustrate a communication system 1 and wireless devicesapplied to the present disclosure.

FIG. 20 illustrates discontinuous reception (DRX) operation applicableto the present disclosure.

BEST MODE

Embodiments of the present disclosure are applicable to a variety ofwireless access technologies such as code division multiple access(CDMA), frequency division multiple access (FDMA), time divisionmultiple access (TDMA), orthogonal frequency division multiple access(OFDMA), and single carrier frequency division multiple access(SC-FDMA). CDMA can be implemented as a radio technology such asUniversal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can beimplemented as a radio technology such as Global System for Mobilecommunications (GSM)/General Packet Radio Service (GPRS)/Enhanced DataRates for GSM Evolution (EDGE). OFDMA can be implemented as a radiotechnology such as Institute of Electrical and Electronics Engineers(IEEE) 802.11 (Wireless Fidelity (Wi-Fi)), IEEE 802.16 (Worldwideinteroperability for Microwave Access (WiMAX)), IEEE 802.20, and EvolvedUTRA (E-UTRA). UTRA is a part of Universal Mobile TelecommunicationsSystem (UMTS). 3rd Generation Partnership Project (3GPP) Long TermEvolution (LTE) is part of Evolved UMTS (E-UMTS) using E-UTRA, andLTE-Advanced (A) is an evolved version of 3GPP LTE. 3GPP NR (New Radioor New Radio Access Technology) is an evolved version of 3GPP LTE/LTE-A.

As more and more communication devices require a larger communicationcapacity, there is a need for mobile broadband communication enhancedover conventional radio access technology (RAT). In addition, massiveMachine Type Communications (MTC) capable of providing a variety ofservices anywhere and anytime by connecting multiple devices and objectsis another important issue to be considered for next generationcommunications. Communication system design considering services/UEssensitive to reliability and latency is also under discussion. As such,introduction of new radio access technology considering enhanced mobilebroadband communication (eMBB), massive MTC, and Ultra-Reliable and LowLatency Communication (URLLC) is being discussed. In the presentdisclosure, for simplicity, this technology will be referred to as NR(New Radio or New RAT).

For the sake of clarity, 3GPP NR is mainly described, but the technicalidea of the present disclosure is not limited thereto. LTE refers totechnologies after 3GPP TS 36.xxx Release 8. Specifically, LTEtechnologies after 3GPP TS 36.xxx Release 10 are referred to as LTE-A,and LTE technologies after 3GPP TS 36.xxx Release 13 are referred to asLTE-A pro. 3GPP NR refers to technologies after TS 38.xxx Release 15.LTE/NR may be referred to as 3GPP systems. In this document, “xxx”represents the detail number of a specification. LTE/NR may becollectively referred to as 3GPP systems.

Details of the background, terminology, abbreviations, etc. used hereinmay be found in documents published before the present disclosure. Forexample, the present disclosure may be supported by the followingdocuments:

3GPP LTE

-   -   36.211: Physical channels and modulation    -   36.212: Multiplexing and channel coding    -   36.213: Physical layer procedures    -   36.300: Overall description    -   36.321: Medium Access Control (MAC)    -   36.331: Radio Resource Control (RRC)

3GPP NR

-   -   38.211: Physical channels and modulation    -   38.212: Multiplexing and channel coding    -   38.213: Physical layer procedures for control    -   38.214: Physical layer procedures for data    -   38.300: NR and NG-RAN Overall Description    -   38.321: Medium Access Control (MAC)    -   38.331: Radio Resource Control (RRC) protocol specification

Technical Terms Used in this Document

-   -   PDCCH: Physical Downlink Control CHannel    -   PDSCH: Physical Downlink Shared CHannel    -   PUSCH: Physical Uplink Shared CHannel    -   CSI: Channel state information    -   RRM: Radio resource management    -   RLM: Radio link monitoring    -   DCI: Downlink Control Information    -   CAP: Channel Access Procedure    -   Ucell: Unlicensed cell    -   PCell: Primary Cell    -   PSCell: Primary SCG Cell    -   TBS: Transport Block Size    -   SLIV: Starting and Length Indicator Value (The SLIV is a field        that indicates the starting symbol index and the number of        symbols in a slot for a PDSCH and/or PUSCH, and the SLIV is        carried on a PDCCH scheduling the corresponding PDSCH and/or        PUSCH.)    -   BWP: BandWidth Part (The BWP may be composed of consecutive        resource blocks (RBs) in the frequency domain, which may        correspond to one numerology (e.g., subcarrier spacing, cyclic        prefix (CP) length, slot/mini-slot duration, etc.). In addition,        multiple BWPs may be configured on one carrier (the number of        BWPs per carrier may be limited), but the number of active BWPs        may be limited in each carrier (e.g., one).)    -   CORESET: COntrol REsourse SET (The CORESET refers to a time        frequency resource region capable of transmitting a PDCCH, and        the number of CORESETs per BWP may be limited.)    -   REG: Resource element group    -   SFI: Slot Format Indicator (The SFI is an indicator that        indicates the DL/UL direction at the symbol level in specific        slot(s), and the SFI is transmitted over a group-common PDCCH.)    -   COT: Channel occupancy time    -   SPS: Semi-persistent scheduling    -   PLMN ID: Public Land Mobile Network identifier    -   RACH: Random Access Channel    -   RAR: Random Access Response    -   Msg3: Message transmitted on UL-SCH containing a C-RNTI MAC CE        or CCCH SDU, submitted from upper layer and associated with the        UE Contention Resolution Identity, as part of a Random Access        procedure.    -   Special Cell: For Dual Connectivity operation the term Special        Cell refers to the PCell of the MCG or the PSCell of the SCG        depending on if the MAC entity is associated to the MCG or the        SCG, respectively. Otherwise the term Special Cell refers to the        PCell. A Special Cell supports PUCCH transmission and        contention-based Random Access, and is always activated.    -   Serving Cell: A PCell, a PSCell, or an SCell

In the present disclosure, the term “set/setting” may be replaced with“configure/configuration”, and both may be used interchangeably.Further, a conditional expression (e.g., “if”, “in a case”, or “when”)may be replaced by “based on that” or “in a state/status”. In addition,an operation or software/hardware (SW/HW) configuration of a userequipment (UE)/base station (BS) may be derived/understood based onsatisfaction of a corresponding condition. When a process on a receiving(or transmitting) side may be derived/understood from a process on thetransmitting (or receiving) side in signal transmission/receptionbetween wireless communication devices (e.g., a BS and a UE), itsdescription may be omitted. Signaldetermination/generation/encoding/transmission of the transmitting side,for example, may be understood as signal monitoringreception/decoding/determination of the receiving side. Further, when itis said that a UE performs (or does not perform) a specific operation,this may also be interpreted as that a BS expects/assumes (or does notexpect/assume) that the UE performs the specific operation. When it issaid that a BS performs (or does not perform) a specific operation, thismay also be interpreted as that a UE expects/assumes (or does notexpect/assume) that the BS performs the specific operation. In thefollowing description, sections, embodiments, examples, options,methods, schemes, proposals and so on are distinguished from each otherand indexed, for convenience of description, which does not mean thateach of them necessarily constitutes an independent disclosure or thateach of them should be implemented only individually. Unless explicitlycontradicting each other, it may be derived/understood that at leastsome of the sections, embodiments, examples, options, methods, schemes,proposals and so on may be implemented in combination or may be omitted.

In a wireless communication system, a user equipment (UE) receivesinformation through downlink (DL) from a base station (BS) and transmitinformation to the BS through uplink (UL). The information transmittedand received by the BS and the UE includes data and various controlinformation and includes various physical channels according totype/usage of the information transmitted and received by the UE and theBS.

FIG. 1 illustrates physical channels used in a 3GPP NR system and ageneral signal transmission method using the same.

When a UE is powered on again from a power-off state or enters a newcell, the UE performs an initial cell search procedure, such asestablishment of synchronization with a BS, in step S101. To this end,the UE receives a synchronization signal block (SSB) from the BS. TheSSB includes a primary synchronization signal (PSS), a secondarysynchronization signal (SSS), and a physical broadcast channel (PBCH).The UE establishes synchronization with the BS based on the PSS/SSS andacquires information such as a cell identity (ID). The UE may acquirebroadcast information in a cell based on the PBCH. The UE may receive aDL reference signal (RS) in an initial cell search procedure to monitora DL channel status.

The SSB is composed of four consecutive OFDM symbols, each carrying thePSS, the PBCH, the SSS/PBCH, or the PBCH. Each of the PSS and the SSSincludes one OFDM symbol by 127 subcarriers, and the PBCH includes threeOFDM symbols by 576 subcarriers. The PBCH is encoded/decoded based onPolar codes, and modulation/demodulation is performed thereon accordingto quadrature phase shift keying (QPSK). The PBCH in the OFDM symbolconsists of data resource elements (REs) to which a complex modulationvalue of the PBCH is mapped, and demodulation reference signal (DMRS)REs to which a DMRS for the PBCH is mapped. Three DMRS REs areconfigured for each RB in the OFDM symbol, and three data REs configuredbetween DMRS REs.

The PSS may be used in detecting a cell ID within a cell ID group, andthe SSS may be used in detecting a cell ID group. The PBCH may be usedin detecting an SSB (time) index and a half-frame. There are 336 cell IDgroups, and each cell ID group includes three cell IDs. Thus, there area total of 1008 cell IDs.

SSBs are periodically transmitted with an SSB periodicity. A default SSBperiodicity assumed by the UE in initial cell search is defined as 20ms. After cell access, the SSB periodicity may be set to one of {5 ms,10 ms, 20 ms, 40 ms, 80 ms, and 160 ms} by the network (e.g., BS). AnSSB burst set may be configured at the beginning of the SSB periodicity.The SSB burst set may be set to a time window of 5 ms (i.e.,half-frame), and the SSB may be repeatedly transmitted up to L timeswithin the SS burst set. The maximum number of SSB transmissions L maybe given depending carrier frequency bands as follows. One slot includesup to two SSBs.

-   -   For frequency range up to 3 GHz, L=4    -   For frequency range from 3 GHz to 6 GHz, L=8    -   For frequency range from 6 GHz to 52.6 GHz, L=64

The time-domain positions of candidate SSBs in the SS burst set may bedefined depending on subcarrier spacings. The time-domain positions ofthe candidate SSBs are indexed from (SSB indices) 0 to L−1 in temporalorder within the SSB burst set (i.e., half-frame).

Multiple SSBs may be transmitted within the frequency span of a carrier.Each SSB may not need to have a unique physical layer cell identifier,but different SSBs may have different physical layer cell identifiers.

The UE may acquire DL synchronization by detecting the SSB. The UE mayidentify the structure of the SSB burst set based on the detected SSB(time) index, and thus the UE may detect a symbol/slot/half-frameboundary. A frame/half-frame number to which the detected SSB belongsmay be identified based on system frame number (SFN) information andhalf-frame indication information.

Specifically, the UE may obtain a 10-bit SFN for a frame to which a PBCHbelongs from the PBCH. Then, the UE may obtain 1-bit half-frameindication information. For example, when the UE detects the PBCH inwhich the half-frame indication bit is set to 0, the UE may determinethat an SSB to which the PBCH belongs is included in the firsthalf-frame of the frame. When the UE detects the PBCH in which thehalf-frame indication bit is set to 1, the UE may determine that an SSBto which the PBCH belongs is included in the second half-frame of theframe. Finally, the UE may obtain the SSB index of the SSB to which thePBCH belongs based on a DMRS sequence and a PBCH payload carried by thePBCH.

After initial cell search, the UE may acquire more specific systeminformation by receiving a physical downlink control channel (PDCCH) andreceiving a physical downlink shared channel (PDSCH) based oninformation of the PDCCH in step S102.

System information (SI) is divided into a master information block (MIB)and a plurality of system information blocks (SIBs). The SI except forthe MIB may be referred to as remaining minimum system information(RMSI). Details thereof will be described in the following.

-   -   The MIB includes information/parameters for monitoring a PDCCH        scheduling a PDSCH carrying SIB1 (SystemInformationBlock1), and        the MIB is transmitted by the BS over the PBCH of an SSB. For        example, the UE may check based on the MIB whether there is a        CORESET for a Type0-PDCCH common search space. The Type0-PDCCH        common search space is a kind of PDCCH search space, which is        used to transmit a PDCCH scheduling an SI message. If the        Type0-PDCCH common search space exists, the UE may determine (1)        a plurality of contiguous RBs and one or more consecutive        symbols included in the CORESET and (ii) a PDCCH occasion (e.g.,        a time-domain location for PDCCH reception, based on information        (e.g., pdcch-ConfigSIB1) in the MIB. If the Type0-PDCCH common        search space does not exist, pdcch-ConfigSIB1 provides        information on a frequency location at which the SSB/SIB1 exists        and information on a frequency range where there are no        SSB/SIB1.    -   SIB1 includes information related to availability and scheduling        (e.g., transmission periodicity, SI-window size, etc.) of the        remaining SIBs (hereinafter referred to as SIBx where x is an        integer more than or equal to 2). For example, SIB1 may indicate        whether SIBx is periodically broadcast or provided at the        request of the UE in an on-demand manner. When SIBx is provided        in an on-demand manner, SIB1 may include information necessary        for the UE to send an SI request. SIB1 is transmitted over a        PDSCH, and a PDCCH scheduling SIB1 is transmitted in the        Type0-PDCCH common search space. That is, SIB1 is transmitted        over the PDSCH indicated by the PDCCH.    -   SIBx is included in the SI message and transmitted on the PDSCH.        Each SI message is transmitted within a periodically occurring        time window (i.e., SI-window).

The UE may perform a random access procedure to access the BS in stepsS103 to S106. For random access, the UE may transmit a preamble to theBS on a physical random access channel (PRACH) (S103) and receive aresponse message for preamble on a PDCCH and a PDSCH corresponding tothe PDCCH (S104). In the case of contention-based random access, the UEmay perform a contention resolution procedure by further transmittingthe PRACH (S105) and receiving a PDCCH and a PDSCH corresponding to thePDCCH (S106).

After the foregoing procedure, the UE may receive a PDCCH/PDSCH (S107)and transmit a physical uplink shared channel (PUSCH)/physical uplinkcontrol channel (PUCCH) (S108), as a general downlink/uplink signaltransmission procedure. Control information transmitted from the UE tothe BS is referred to as uplink control information (UCI). The UCIincludes hybrid automatic repeat and requestacknowledgement/negative-acknowledgement (HARQ-ACK/NACK), schedulingrequest (SR), channel state information (CSI), etc. The CSI includes achannel quality indicator (CQI), a precoding matrix indicator (PMI), arank indicator (RI), etc. While the UCI is transmitted on a PUCCH ingeneral, the UCI may be transmitted on a PUSCH when control informationand traffic data need to be simultaneously transmitted. In addition, theUCI may be aperiodically transmitted through a PUSCH according torequest/command of a network.

FIG. 2 illustrates a radio frame structure. In NR, uplink and downlinktransmissions are configured with frames. Each radio frame has a lengthof 10 ms and is divided into two 5-ms half-frames (HF). Each half-frameis divided into five 1-ms subframes (SFs). A subframe is divided intoone or more slots, and the number of slots in a subframe depends onsubcarrier spacing (SCS). Each slot includes 12 or 14 OrthogonalFrequency Division Multiplexing (OFDM) symbols according to a cyclicprefix (CP). When a normal CP is used, each slot includes 14 OFDMsymbols. When an extended CP is used, each slot includes 12 OFDMsymbols.

Table 1 exemplarily shows that the number of symbols per slot, thenumber of slots per frame, and the number of slots per subframe varyaccording to the SCS when the normal CP is used.

TABLE 1 SCS (15 * 2{circumflex over ( )}u) N ^(slot) _(symb) N ^(fame,u)_(slot) N ^(subframe,u) _(slot)  15 KHz (u = 0) 14 10 1  30 KHz (u = 1)14 20 2  60 KHz (u = 2) 14 40 4 120 KHz (u = 3) 14 80 8 240 KHz (u = 4)14 160 16

N^(slot) _(symb): Number of symbols in a slot

N^(frame,u) _(slot): Number of slots in a frame

N^(subframe,u) _(slot): Number of slots in a subframe

Table 2 illustrates that the number of symbols per slot, the number ofslots per frame, and the number of slots per subframe vary according tothe SCS when the extended CP is used.

TABLE 2 SCS (15 * 2{circumflex over ( )}u) N ^(slot) _(symb) N ^(fame,u)_(slot) N ^(subframe,u) _(slot) 60 KHz (u = 2) 12 40 4

The structure of the frame is merely an example. The number ofsubframes, the number of slots, and the number of symbols in a frame mayvary.

In the NR system, OFDM numerology (e.g., SCS) may be configureddifferently for a plurality of cells aggregated for one UE. Accordingly,the (absolute time) duration of a time resource (e.g., an SF, a slot ora TTI) (for simplicity, referred to as a time unit (TU)) consisting ofthe same number of symbols may be configured differently among theaggregated cells. Here, the symbols may include an OFDM symbol (or aCP-OFDM symbol) and an SC-FDMA symbol (or a discrete Fouriertransform-spread-OFDM (DFT-s-OFDM) symbol).

FIG. 3 illustrates a resource grid of a slot. A slot includes aplurality of symbols in the time domain. For example, when the normal CPis used, the slot includes 14 symbols. However, when the extended CP isused, the slot includes 12 symbols. A carrier includes a plurality ofsubcarriers in the frequency domain. A resource block (RB) is defined asa plurality of consecutive subcarriers (e.g., 12 consecutivesubcarriers) in the frequency domain. A bandwidth part (BWP) may bedefined to be a plurality of consecutive physical RBs (PRBs) in thefrequency domain and correspond to a single numerology (e.g., SCS, CPlength, etc.). The carrier may include up to N (e.g., 5) BWPs. Datacommunication may be performed through an activated BWP, and only oneBWP may be activated for one UE. In the resource grid, each element isreferred to as a resource element (RE), and one complex symbol may bemapped to each RE.

Bandwidth Part (BWP)

The NR system may support up to 400 MHz for each carrier. The networkmay instruct the UE to operate only in a partial bandwidth rather thanthe whole bandwidth of such a wideband carrier. The partial bandwidth isreferred to as a BWP. The BWP refers to a subset of contiguous commonRBs defined for a numerology in the BWP of a carrier in the frequencydomain, and one numerology (e.g., SCS, CP length, slot/mini-slotduration, etc.) may be configured.

Activation/deactivation of a DL/UL BWP or BWP switching may be performedaccording to network signaling and/or timers (e.g., L1 signalingcorresponding to a physical layer control signal, a MAC control elementcorresponding to a MAC layer control signal, RRC signaling, etc.). Whileperforming initial access or before setting up an RRC connection, the UEmay not receive any DL/UL BWP configurations. A DL/UL BWP that the UEassumes in this situation is referred to as an initial active DL/UL BWP.

Regarding to the initial DL BWP, the following UE operations are definedin 3GPP NR specifications.

-   -   For a DL BWP, if a UE is not provided searchSpaceSIB1 for        Type0-PDCCH CSS set by PDCCH-ConfigCommon, the UE does not        monitor PDCCH candidates for a Type0-PDCCH CSS set on the DL        BWP. The Type0-PDCCH CSS set is defined by the CCE aggregation        levels and the number of PDCCH candidates per CCE aggregation        level. If the active DL BWP and the initial DL BWP have same SCS        and same CP length and the active DL BWP includes all RBs of the        CORESET with index 0, or the active DL BWP is the initial DL        BWP, the CORESET configured for Type0-PDCCH CSS set has CORESET        index 0 and the Type0-PDCCH CSS set has search space set index        0.    -   A UE configured for operation in bandwidth parts (BWPs) of a        serving cell, is configured by higher layers for the serving        cell a set of at most four bandwidth parts (BWPs) for receptions        by the UE (DL BWP set) in a DL bandwidth by parameter        BWP-Downlink or by parameter initialDownlinkBWP with a set of        parameters configured by BWP-DownlinkCommon and        BWP-DownlinkDedicated, and a set of at most four BWPs for        transmissions by the UE (UL BWP set) in an UL bandwidth by        parameter BWP-Uplink or by parameter initialUplinkBWP with a set        of parameters configured by BWP-UplinkCommon and        BWP-UplinkDedicated.    -   If a UE is not provided initialDownlinkBWP, an initial DL BWP is        defined by a location and number of contiguous PRBs, starting        from a PRB with the lowest index and ending at a PRB with the        highest index among PRBs of a CORESET for Type0-PDCCH CSS set,        and a SCS and a cyclic prefix for PDCCH reception in the CORESET        for Type0-PDCCH CSS set; otherwise, the initial DL BWP is        provided by initialDownlinkBWP. For operation on the primary        cell or on a secondary cell, a UE is provided an initial UL BWP        by initialUplinkBWP. If the UE is configured with a        supplementary UL carrier, the UE can be provided an initial UL        BWP on the supplementary UL carrier by initialUplinkBWP.    -   If a UE is provided controlResourceSetZero and searchSpaceZero        in PDCCH-ConfigSIB1 or PDCCH-ConfigCommon, the UE determines a        CORESET for a search space set from controlResourcesetZero, and        determines corresponding PDCCH monitoring occasions. If the        active DL BWP is not the initial DL BWP, the UE determines PDCCH        monitoring occasions for the search space set only if the        CORESET bandwidth is within the active DL BWP and the active DL        BWP has same SCS configuration and same cyclic prefix as the        initial DL BWP.    -   For a serving cell, a UE can be provided by        defaultDownlinkBWP-Id a default DL BWP among the configured DL        BWPs. If a UE is not provided a default DL BWP by        defaultDownlinkBWP-Id, the default DL BWP is the initial DL BWP.

FIG. 4 illustrates an exemplary normal random access procedure.Specifically, FIG. 4 shows a contention-based random access procedure ofthe UE, which is performed in four steps.

First, the UE may transmit message 1 (Msg1) including a random accesspreamble on a PRACH (see 1701 of FIG. 4(a)).

Random access preamble sequences with different lengths may besupported. A long sequence length of 839 may be applied to SCSs of 1.25and 5 kHz, and a short sequence length of 139 may be applied to SCSs of15, 30, 60, and 120 kHz.

Multiple preamble formats may be defined by one or more RACH OFDMsymbols and different CPs (and/or guard times). A RACH configuration fora cell may be included in SI about the cell and provided to the UE. TheRACH configuration may include information on the SCS of the PRACH,available preambles, preamble formats, and so on. The RACH configurationmay include information about association between SSBs and RACH(time-frequency) resources. The UE transmits a random access preamble ona RACH time-frequency resource associated with a detected or selectedSSB.

The threshold of an SSB for RACH resource association may be configuredby the network, and a RACH preamble may be transmitted or retransmittedbased on an SSB where reference signal received power (RSRP), which ismeasured based on the SSB, satisfies the threshold. For example, the UEmay select one SSB from among SSBs that satisfy the threshold andtransmit or retransmit the RACH preamble based on a RACH resourceassociated with the selected SSB.

Upon receiving the random access preamble from the UE, the BS maytransmit message 2 (Msg2) corresponding to a random access response(RAR) message to the UE (see 1703 of FIG. 4(a)). A PDCCH scheduling aPDSCH carrying the RAR may be CRC masked with a random access (RA) radionetwork temporary identifier (RNTI) (RA-RNTI) and then transmitted. Upondetecting the PDCCH masked by the RA-RNTI, the UE may obtain the RARfrom the PDSCH scheduled by DCI carried by the PDCCH. The UE may checkwhether the RAR includes RAR information in response to the preambletransmitted by the UE, i.e., Msg1. The presence or absence of the RARinformation in response to Msg1 transmitted by the UE may be determineddepending on whether there is a random access preamble ID for thepreamble transmitted by the UE. If there is no response to Msg1, the UEmay retransmit the RACH preamble within a predetermined number of timeswhile performing power ramping. The UE may calculate PRACH transmitpower for retransmitting the preamble based on the most recent path lossand power ramping counter.

The RAR information transmitted on the PDSCH may include timing advance(TA) information for UL synchronization, an initial UL grant, and atemporary cell-RNTI (C-RNTI). The TA information may be used to controla UL signal transmission timing. The UE may transmit a UL signal over aUL shared channel as message 3 (Msg3) of the random access procedurebased on the RAR information (see 1705 of FIG. 4(a)). Msg3 may includean RRC connection request and a UE identifier. In response to Msg3, thenetwork may transmit message 4 (Msg4), which may be treated as acontention resolution message on DL (see 1707 of FIG. 4(a)). Uponreceiving Msg4, the UE may enter the RRC_CONNECTED state.

On the other hand, a contention-free random access procedure may beperformed when the UE is handed over to another cell or BS or when it isrequested by the BS. In the contention-free random access procedure, apreamble to be used by the UE (hereinafter referred to as a dedicatedrandom access preamble) is allocated by the BS. Information on thededicated random access preamble may be included in an RRC message(e.g., handover command) or provided to the UE through a PDCCH order.When the random access procedure is initiated, the UE may transmit thededicated random access preamble to the BS. When the UE receives an RARfrom the BS, the random access procedure is completed.

As described above, a UL grant in the RAR may schedule PUSCHtransmission to the UE. A PUSCH carrying initial UL transmission basedon the UL grant in the RAR is referred to as an Msg3 PUSCH. The contentof an RAR UL grant may start at the MSB and end at the LSB, and thecontent may be given as shown in Table 3.

TABLE 3 Number of RAR UL grant field bits Frequency hopping flag 1 Msg3PUSCH frequency resource 12  allocation Msg3 PUSCH time resourceallocation 4 Modulation and coding scheme (MKS) 4 Transmit power control(TPC) for 3 Msg3 PUSCH CSI request 1

FIG. 5 illustrates exemplary mapping of physical channels in a slot. APDCCH may be transmitted in a DL control region, and a PDSCH may betransmitted in a DL data region. A PUCCH may be transmitted in a ULcontrol region, and a PUSCH may be transmitted in a UL data region. Aguard period (GP) provides a time gap for transmission mode-to-receptionmode switching or reception mode-to-transmission mode switching at a BSand a UE. Some symbol at the time of DL-to-UL switching in a subframemay be configured as a GP.

Each physical channel will be described below in greater detail.

The PDCCH delivers DCI. For example, the PDCCH (i.e., DCI) may carryinformation about a transport format and resource allocation of a DLshared channel (DL-SCH), resource allocation information of an uplinkshared channel (UL-SCH), paging information on a paging channel (PCH),system information on the DL-SCH, information on resource allocation ofa higher-layer control message such as an RAR transmitted on a PDSCH, atransmit power control command, information about activation/release ofconfigured scheduling, and so on. The DCI includes a cyclic redundancycheck (CRC). The CRC is masked with various identifiers (IDs) (e.g. aradio network temporary identifier (RNTI)) according to an owner orusage of the PDCCH. For example, if the PDCCH is for a specific UE, theCRC is masked by a UE ID (e.g., cell-RNTI (C-RNTI)). If the PDCCH is fora paging message, the CRC is masked by a paging-RNTI (P-RNTI). If thePDCCH is for system information (e.g., a system information block(SIB)), the CRC is masked by a system information RNTI (SI-RNTI). Whenthe PDCCH is for an RAR, the CRC is masked by a random access-RNTI(RA-RNTI).

The PDCCH includes 1, 2, 4, 8, or 16 control channel elements (CCEs)according to its aggregation level (AL). A CCE is a logical allocationunit used to provide a PDCCH with a specific code rate according to aradio channel state. A CCE includes 6 resource element groups (REGs),each REG being defined by one OFDM symbol by one (P)RB. The PDCCH istransmitted in a control resource set (CORESET). A CORESET is defined asa set of REGs with a given numerology (e.g., an SCS, a CP length, and soon). A plurality of CORESETs for one UE may overlap with each other inthe time/frequency domain. A CORESET may be configured by systeminformation (e.g., a master information block (MIB)) or UE-specifichigher-layer signaling (e.g., radio resource control (RRC) signaling).Specifically, the number of RBs and the number of symbols (3 at maximum)in the CORESET may be configured through higher-layer signaling.

For PDCCH reception/detection, the UE monitors PDCCH candidates. A PDCCHcandidate is CCE(s) that the UE should monitor to detect a PDCCH. EachPDCCH candidate is defined as 1, 2, 4, 8, or 16 CCEs according to an AL.The monitoring includes (blind) decoding PDCCH candidates. A set ofPDCCH candidates decoded by the UE are defined as a PDCCH search space(SS). An SS may be a common search space (CSS) or a UE-specific searchspace (USS). The UE may obtain DCI by monitoring PDCCH candidates in oneor more SSs configured by an MIB or higher-layer signaling. Each CORESETis associated with one or more SSs, and each SS is associated with oneCORESET. An SS may be defined based on the following parameters.

-   -   controlResourceSetId: A CORESET related to an SS.    -   monitoringSlotPeriodicityAndOffset: A PDCCH monitoring        periodicity (in slots) and a PDCCH monitoring offset (in slots).    -   monitoringSymbolsWithinSlot: PDCCH monitoring symbols in a slot        (e.g., the first symbol(s) of a CORESET).    -   nrofCandidates: The number of PDCCH candidates (one of 0, 1, 2,        3, 4, 5, 6, and 8) for each AL={1, 2, 4, 8, 16}.    -   An occasion (e.g., time/frequency resources) in which the UE is        to monitor PDCCH candidates is defined as a PDCCH (monitoring)        occasion. One or more PDCCH (monitoring) occasions may be        configured in a slot.

Table 4 shows the characteristics of each SS.

TABLE 4 Search Type Space RNTI Use Case Type0-PDCCH Common SI-RNTI on aprimary cell SIB Decoding Type0A-PDCCH Common SI-RNTI on a primary cellSIB Decoding Type1-PDCCH Common RA-RNTI or TC-RNTI on a primary cellMsg2, Msg4 decoding in RACH Type2-PDCCH Common P-RNTI on a primary cellPaging Decoding Type3-PDCCH Common INT-RNTI, SFI-RNTI, TPC-PUSCH-RNTI,TPC-PUCCH-RNTI, TPC-SRS-RNTI, C-RNTI, MCS-C-RNTI, or CS-RNTI(s) UESpecific C-RNTI, or MCS-C-RNTI, or CS-RNTI(s) User specific PDSCHdecoding

Table 5 shows DCI formats transmitted on the PDCCH.

TABLE 5 DCI format Usage 0_0 Scheduling of PUS CH in one cell 0_1Scheduling of PUS CH in one cell 1_0 Scheduling of PDSCH in one cell 1_1Scheduling of PDSCH in one cell 2_0 Notifying a group of UEs of the slotformat 2_1 Notifying a group of UEs of the PRB(s) and OFDM symbol(s)where UE may assume no transmission is intended for the UE 2_2Transmission of TPC commands for PUCCH and PUSCH 2_3 Transmission of agroup of TPC commands for SRS transmissions by one or more UEs

DCI format 0_0 may be used to schedule a TB-based (or TB-level) PUSCH,and DCI format 0_1 may be used to schedule a TB-based (or TB-level)PUSCH or a code block group (CBG)-based (or CBG-level) PUSCH. DCI format1_0 may be used to schedule a TB-based (or TB-level) PDSCH, and DCIformat 1_1 may be used to schedule a TB-based (or TB-level) PDSCH or aCBG-based (or CBG-level) PDSCH (DL grant DCI). DCI format 0_0/0_1 may bereferred to as UL grant DCI or UL scheduling information, and DCI format1_0/1_1 may be referred to as DL grant DCI or DL scheduling information.DCI format 2_0 is used to deliver dynamic slot format information (e.g.,a dynamic slot format indicator (SFI)) to a UE, and DCI format 2_1 isused to deliver DL pre-emption information to a UE. DCI format 2_0and/or DCI format 2_1 may be delivered to a corresponding group of UEson a group common PDCCH which is a PDCCH directed to a group of UEs.

DCI format 0_0 and DCI format 1_0 may be referred to as fallback DCIformats, whereas DCI format 0_1 and DCI format 1_1 may be referred to asnon-fallback DCI formats. In the fallback DCI formats, a DCI size/fieldconfiguration is maintained to be the same irrespective of a UEconfiguration. In contrast, the DCI size/field configuration variesdepending on a UE configuration in the non-fallback DCI formats.

The PDSCH conveys DL data (e.g., DL-shared channel transport block(DL-SCH TB)) and uses a modulation scheme such as quadrature phase shiftkeying (QPSK), 16-ary quadrature amplitude modulation (16QAM), 64QAM, or256QAM. A TB is encoded into a codeword. The PDSCH may deliver up to twocodewords. Scrambling and modulation mapping may be performed on acodeword basis, and modulation symbols generated from each codeword maybe mapped to one or more layers. Each layer together with a demodulationreference signal (DMRS) is mapped to resources, and an OFDM symbolsignal is generated from the mapped layer with the DMRS and transmittedthrough a corresponding antenna port.

The PUCCH delivers uplink control information (UCI). The UCI includesthe following information.

-   -   SR (Scheduling Request): Information used to request UL-SCH        resources.    -   HARQ (Hybrid Automatic Repeat reQuest)-ACK (Acknowledgement): A        response to a DL data packet (e.g., codeword) on the PDSCH. An        HARQ-ACK indicates whether the DL data packet has been        successfully received. In response to a single codeword, a 1-bit        of HARQ-ACK may be transmitted. In response to two codewords, a        2-bit HARQ-ACK may be transmitted. The HARQ-ACK response        includes positive ACK (simply, ACK), negative ACK (NACK),        discontinuous transmission (DTX) or NACK/DTX. The term HARQ-ACK        is interchangeably used with HARQ ACK/NACK and ACK/NACK.    -   CSI (Channel State Information): Feedback information for a DL        channel. Multiple input multiple output (MIMO)-related feedback        information includes an RI and a PMI.

The PUSCH delivers UL data (e.g., UL-shared channel transport block(UL-SCH TB)) and/or UCI based on a CP-OFDM waveform or a DFT-s-OFDMwaveform. When the PUSCH is transmitted in the DFT-s-OFDM waveform, theUE transmits the PUSCH by transform precoding. For example, whentransform precoding is impossible (e.g., disabled), the UE may transmitthe PUSCH in the CP-OFDM waveform, while when transform precoding ispossible (e.g., enabled), the UE may transmit the PUSCH in the CP-OFDMor DFT-s-OFDM waveform. A PUSCH transmission may be dynamicallyscheduled by a UL grant in DCI, or semi-statically scheduled byhigher-layer (e.g., RRC) signaling (and/or Layer 1 (L1) signaling suchas a PDCCH) (configured scheduling or configured grant). The PUSCHtransmission may be performed in a codebook-based or non-codebook-basedmanner.

Initial DL BWP Selection and Common Channel Reception for Cell Access ofUE

In general, the UE needs to support specific UE capability in order toaccess a cell. For example, to access an LTE cell, the UE needs to becapable of receiving an MIB and SIB(s) broadcast for the cell by the BS.Since there are several types of SIB (e.g., SIB1, SIB2 . . . , SIBx-y,etc.) and the SIB is transmitted in a plurality of PRBs, the UEintending to access the LTE cell needs to have an ability to receive abandwidth of 20 MHz at least.

To access an NR cell, the UE needs to be capable of receiving an MIB inan SSB/PBCH transmitted in an initial DL BWP. Even when the UE iscapable of receiving the SSB/PBCH, the UE also needs to check whetherthe UE is allowed to access the corresponding cell, based on cell accessinformation included in SIB1. To this end, the UE may check whetherthere is a CORESET for a Type0-PDCCH common search space (CSS), based onthe MIB. If the Type0-PDCCH CSS exists, the UE may determine CORSET #0and a PDCCH occasion based on information in the MIB (e.g.,pdcch-ConfigSIB1). Then, the UE may receive SIB1 over a PDSCH indicatedby a PDCCH received on the corresponding PDCCH occasion.

Upon receiving the SIB, the UE needs to check various information todetermine whether the UE is allowed to access the cell. If theinformation does not satisfy some conditions, the UE may set thecorresponding cell as an access-prohibited cell. For example, themaximum UL channel bandwidth supported by the UE needs to be greaterthan or equal to the bandwidth of an initial UL BWP, and the maximum DLchannel bandwidth supported by the UE needs be greater than or equal tothe bandwidth of the initial DL BWP. If this condition is not satisfied,the UE may set the corresponding cell as the access-prohibited cell.

REL-17 NR intends to support a new type of UE with reduced capability.This type of UE is called an R-terminal or R-UE different from thelegacy REL-15 UE.

Since the UE capability of the R-UE is limited compared to that of thelegacy UE, a problem may occur in the cell access process. For example,the R-UE may be incapable of receiving the MIB in the initial DL BWP ofthe legacy NR cell. In addition, even if the R-UE is allowed to receivethe MIB, the R-UE may be incapable of receiving a PDCCH schedulingCORSET #0 or SIB1. Alternatively, the maximum UL channel bandwidth ormaximum DL channel bandwidth of the R-UE may not be greater than orequal to the bandwidth of the initial BWP supported by legacy NR cells.Alternatively, considering the numerology supported by the initial BWPof the legacy cell, the R-UE may not receive a paging messagetransmitted from the BS or may not perform UL RACH transmission forinitial access due to the SCS. Due to these problems, a normal NR cellmay be set as the access-prohibited cell frequently from the perspectiveof the R-UE.

The BS may need to provide a common channel transmission/receptionmethod suitable for the R-UE at the beginning of the initial accessprocess for the following reasons. First, the legacy UE may receive upto four transmissions: paging, MIB, SIB1, and unicast, based onfrequency division multiplexing (FDM), but the number of channels thatthe R-UE is capable of simultaneously receiving may decrease due to thelimited capability of the R-UE. Second, the numerology required for userservices suitable for the R-UE may be different from the numerologyaccessible by normal UEs, and thus, the numerology of the initial BWP ofthe legacy cell may not be suitable for the R-UE. Third, the cellcoverage of the R-UE may be reduced compared to that of the legacy UEdue to limited RF capability. Finally, the R-UE may require an improvedpower saving technique compared to the legacy UE.

Therefore, the present disclosure proposes a method in which when anR-UE with limited capability performs initial access to a wirelessnetwork system through one cell, a BS managing the corresponding cellprovides an initial DL BWP available to the R-UE. In particular, the BSmay provide two or more initial DL BWPs for the cell, and the UE mayselect one initial DL BWP from among a plurality of initial DL BWPsdepending on the capability supported by the UE. In addition, the UE mayreceive a common channel of the cell and then receive systeminformation, paging messages, or RAR messages over the common channel.

The following operations may be provided in order for the UE to receivea DL common channel.

FIG. 9 is a diagram for explaining UE operations in an initial DL BWPaccording to an embodiment of the present disclosure.

Referring to FIG. 9 , the UE may detect a synchronization channel andreceive master information for a cell (A05). The synchronization channelmay correspond to an SSB. The master information may correspond to anMIB.

The UE may determine whether to configure a second initial DL BWPcompatible with a second type of UEs based on the capability of the UE(A10).

The second type of UEs may have reduced capability compared to a firsttype of UEs corresponding to Rel-15 NR UEs.

The second initial DL BWP may be compatible with at least the secondtype of UEs, while the first initial DL BWP may be compatible with atleast the first type of UEs.

The second initial DL BWP may provide a smaller number of PRBs than thefirst initial DL BWP.

-   -   If the capability of the UE is incapable of supporting the first        initial DL BWP of the cell, or if the second initial UL BWP is        associated with the second type of UEs (the association may be        indicated by system information of the cell),    -   The UE may switch to the second initial DL BWP (A15) to receive        a common channel carrying common information (A20).

The UE may activate the second initial DL BWP while deactivating thefirst initial DL BWP (A15).

For the UE, the priority of the second initial DL BWP may be higher thanthe priority of the first initial DL BWP.

The common channel or the common information may be prioritized overother channels or other information.

-   -   The UE may switch back to the first initial DL BWP to receive        the synchronization channel and/or the master information (e.g.,        to perform idle measurement). The UE may activate the first        initial DL BWP while deactivating the second initial DL BWP.    -   The UE may access to the cell based on the common information.

The UE may perform RF retuning to switch to one of the BWPs.

The common channel may correspond to one of a PDCCH, a PDSCH and a PBCH.

The common information may correspond to one of system information,system information modification, a short message, a paging message, awarning message, and a warning message indicator.

Hereinafter, the second initial DL BWP is referred to as an initial DLR-BWP, and the first initial DL BWP is referred to as a (legacy) initialDL BWP. In addition, the second type of UE is referred to as anR-terminal, an R-UE, or a UE (of the present disclosure), and the firsttype of UE is referred to as a legacy UE or a conventional UE.

1) SI Transmission Side (e.g., BS):

In an example of present disclosure, if the R-UE is incapable ofreceiving legacy SIB1 transmission, if legacy SIB1 is not related to theR-UE, or if the R-UE needs to receive additional R-UE-dedicatedinformation in addition to the legacy SIB1 information, the R-UE mayreceive new SIB1. For convenience, SIB1 capable of being receiving bythe R-UE is referred to as R-SIB1. R-SIB1 may include all or part ofconfiguration information included in legacy SIB1, and R-SIB1 may alsoinclude configuration information dedicated to the R-UE. The legacy UEmay not receive R-SIB1.

In this case, from the viewpoint of the BS, one cell needs tosimultaneously operate two types of SIB1: SIB1 and R-SIB1. One type ofMIB may be mapped to the two types of SIB1. Alternatively, an MIB may bemapped to legacy SIB1, and legacy SIB1 may be mapped to R-SIB1. Here,the mapping may mean logical mapping between SIBs that arerelated/linked to each other. In addition, legacy SIB1 and R-SIB1 mayinclude scheduling information (e.g., schedulingInfoList) informingwhether other SIBs are broadcast or not and transmission periodsthereof.

One cell may simultaneously operate legacy SIBx and new SIBx. New SIBxmay include R-UE-dedicated information or information not related tolegacy UEs, which is referred to as R-SIBx. For example, in the case ofSIB3 including infra-frequency cell reselection information, one cellmay transmit legacy SIB3 and R-SIB3 together. In this case, legacy SIB3may be used by the legacy UE to perform cell reselection, and R-SIB3 maybe used by the R-UE to perform cell reselection. If legacy SIBx does notinclude R-UE-dedicated information, or if the R-UE-dedicated informationis included only in R-SIBx, scheduling information for R-SIB1 may informwhether R-SIBx is broadcast and a transmission period thereof, andscheduling information for legacy SIB1 may inform whether legacy SIBx isbroadcast and a transmission period thereof.

On the other hand, legacy SIBx may also include information related tofor both the R-UE and the legacy UE. In this case, the schedulinginformation for legacy SIB1 and the scheduling information for R-SIB1may schedule legacy SIBx together. For example, in the case of SIB6 orSIB7 broadcasting a public warning message, the scheduling informationfor legacy SIB1 and the scheduling information for R-SIB1 may scheduleeither SIB6 or SIB7 together. Alternatively, the scheduling informationfor legacy SIB1 and the scheduling information for R-SIB1 may scheduleR-SIBx together.

2) SI Reception Side (e.g., UE):

[Proposal #1] when Selecting an Initial Cell, the R-UE May Proceed witha Legacy Initial DL BWP Until Receiving at Least an MIB from the ServingCell. After Receiving the MIB, the R-UE May Switch to an Initial DLR-BWP and Perform System Information, Paging, and Random AccessOperations.

FIG. 10 illustrates an exemplary initial access process according toProposal #1.

For example, the R-UE may receive an MIB from a selected cell during aninitial cell selection process, a measurement process, and/or a mobilityprocess such as handover (B05).

The R-UE may determine a CSS and/or CORESET0 for the R-UE (B10).

For example, the R-UE may check whether there is a CORESET for aType0-PDCCH CSS, i.e., CORESET0, based on the received MIB. CORESET0 forthe Type0-PDCCH CSS for the R-UE may be configured in common to both thelegacy UE and R-UE (e.g., BWP switching to R-BWP at timing t1 in FIG. 12), or CORESET0 for the Type0-PDCCH CSS for the R-UE may be configuredonly for the R-UE (e.g., BWP switching to R-BWP at timing t1 in FIG. 13). For example, if the R-UE supports legacy CORESET0, legacy CORESET0and a legacy Type0-PDCCH CSS may be defined/used as CORESET0 for theR-UE and the Type0-PDCCH CSS for the R-UE, respectively. In this case,the R-UE may receive a PDCCH in legacy CORESET0/CSS. On the other hand,if the R-UE is incapable of supporting legacy CORESET0, or if the R-UEis incapable of using legacy CORESET0, CORESET0 for the R-UE and theType0-PDCCH CSS for the R-UE may be defined/configured/used,independently of legacy CORESET0 and the legacy Type0-PDCCH CSS. In thiscase, the R-UE may receive a PDCCH in CORESET0/CSS dedicated to theR-UE. A part or all of a Type0-PDCCH CSS for the legacy UE may becombined with an additional Type0-PDCCH CSS dedicated to the R-UE inorder to configure a CSS for the R-UE.

For example, when the CSS for the R-UE exists in the initial cellselection process, the measurement process, and/or the mobility processsuch as handover, the UE may determine (i) a plurality of contiguous RBsand one or more contiguous symbols, which are included in CORESET0; and(ii) a PDCCH occasion (i.e., a time-domain location for PDCCHreception), based on information in the SSB or MIB (e.g.,pdcch-ConfigSIB1). For example, CORESET0 determined by pdcch-ConfigSIB1may be CORESET0 for the legacy UE, and CORESET0 for the R-UE may beconfigured by an offset from CORESET0 for the legacy UE (e.g., FIG.13(b)). The position of CORESET0 for the R-UE may be determined suchthat the position of CORESET0 for the legacy UE is shifted by either orboth of a time-domain offset or a frequency-domain offset. For example,the corresponding frequency-domain offset may be configured at the RBand/or RE level, and in this case, the RB level offset may vary for eachfrequency band. The frequency-domain offset may be defined as an offsetbetween the first or last RB of an SSB/PBCH and the first RB of CORESET0for the R-UE, or the frequency-domain offset may be defined as an offsetbetween the first or last RB of legacy CORESET0 and the first or last RBof CORESET0 for the R-UE. On the other hand, the time-domain offset maybe set to the number of symbols. When the offset is zero, CORESET0 forthe R-UE may be defined in the same symbol as the SSB/PBCH or legacyCORESET0. When the offset is not zero, CORESET0 for the R-UE may beconfigured to be located before or after the time-domain offset from theSSB/PBCH or legacy CORESET0. The value or range of the offset may besignaled by the network (e.g., indicated by reserved bits of the MIB),or the offset may have a fixed value. As an example in which the valueor range of the offset is fixed, a fixed offset value or a fixed offsetrange may be predefined/preconfigured for each frequency band.

For example, when there is no CSS for the R-UE during the initial cellselection process, the measurement process, and/or the mobility processsuch as handover, the PBCH payload (e.g., pdcch-ConfigSIB1 or otherinformation in the MIB) may provide (i) information on a frequencylocation at which an SSB/SIB1 for the legacy UE or an SSB/R-SIB1 for theR-UE is expected; and/or (ii) information on a frequency range wherethere are no SSB/SIB1 for the legacy UE or no SSB/R-SIB1 for the R-UE(e.g., for UE re-direction). For example, the BS may indicate whetherthe provided information: information (i) and/or (ii) is for the legacyUE or for the R-UE, based on the MIB (e.g., using reserved bits of theMIB). For example, the BS may use the MIB (e.g., reserved bits of theMIB) to inform whether the R-UE needs to measure corresponding resourcesfor cell reselection, mobility, or automatic neighbor relation (ANR).The R-UE may detect the frequency location of the SSB/R-SIB1 for theR-UE based on the provided information: information (i) and/or (ii).After receiving the MIB, the R-UE may determine CORESET0 and a PDCCHoccasion (e.g., PDCCH monitoring occasion) for the R-UE.

The CSS and/or CORESET0 for the R-UE may be determined according to theabove-described process. For example, if the CSS and CORESET0 for theR-UE are different from CORESET0 of the legacy UE, or if CORESET0 forthe R-UE is out of the legacy initial DL BWP, the R-UE may determinethat an initial DL R-BWP, which is determined in association withCORESET0 for the R-UE, is activated, active, or valid. On the otherhand, the R-UE may determine that the initial DL BWP for the legacy UEis deactivated, inactive, or invalid.

In the NR system, PDCCH transmission and reception may be performedbased on blind decoding of resources configured by a CORESET and searchspace set. The CORESET defines the region and characteristics ofresources in which the PDCCH is capable of being transmitted. Regardingthe resource region, the size and location of the CORESET in thefrequency domain and the size of the CORESET in the time domain may begiven by the BS (the time-domain location for monitoring a PDCCHcandidate in the CORESET may be determined by the search space set).

As shown in FIG. 10 , when the CSS is determined, the R-UE may detect aDCI format with a CRC scrambled by a specific RNTI by monitoring a PDCCHfor scheduling R-SIB1 during a corresponding period. In this case, thespecific RNTI may be a legacy SI-RNTI or an RNTI for R-SIB1 reception(e.g., R-UE-dedicated SI-RNTI). The DCI format may be defined as alegacy DCI format or a DCI format dedicated to the R-UE.

The DCI format for R-SIB1 may include at least some of the followinginformation.

-   -   FDRA (Frequency domain resource assignment): Ceiling        [log₂{N_(RB) ^(DL,BWP)(N_(RB) ^(DL,BWP)+1)/2}] bits, where        N_(RB) ^(DL,BWP) is defined by the size of CORESET0.    -   TDRA (Time domain resource assignment)    -   VRB-to-PRB mapping    -   MCS (Modulation and coding scheme)    -   RV (Redundancy Version)    -   Aggregation factor: The aggregation factor indicates the number        of times that R-SIB1 is repeatedly transmitted (repetition        number).    -   SI (System information) indicator: The SI indicator indicates        whether SIB1 is R-SIB1 or legacy SIB1 and/or whether SIBx is        R-SIBx or legacy SIBx.    -   Reserved bit(s)

For the R-UE, R-SIB1 may include information similar to that in legacySIB1. For example, R-SIB1 may include at least some of the followinginformation.

-   -   Scheduling Information: Information on whether SIBx shared by        the legacy UE and R-UE is broadcast or a transmission period        thereof, or information on whether R-SIBx dedicated to the R-UE        is broadcast or a transmission period thereof    -   RACH Configuration Information: RACH configuration information        shared by the legacy UE and R-UE or RACH configuration        information dedicated to the R-UE    -   Initial UL BWP Information: Initial UL BWP configuration        information shared by the legacy UE and R-UE or initial UL BWP        configuration information dedicated to the R-UE    -   Access Control Information (Access Control Parameters):        Probability-based access control information shared by the        legacy UE and R-UE or probability-based access control        information dedicated to the R-UE. When there are multiple types        of R-UEs, the access control information may carry a different        parameter value for each type of R-UE. The R-UE may determine        whether UL transmission for initial access is allowed based on        probability, using parameter values (e.g., barring factor and        barring time) corresponding to the type of the R-UE.

The UE may request or receive transmission of R-SIBx dedicated to theR-UE based on the scheduling information.

Thereafter, the R-UE may receive an RAR (Msg2) or a contentionresolution message (Msg4) in the initial DL R-BWP during the randomaccess process. Then, the R-UE may receive a paging indicator or apaging message.

Meanwhile, priorities may be given to an MIB, SIB1, R-SIB1, and/ordifferent (R-)SIBx. For example, the priorities may be configured byR-SIB1. When the MIB, SIB1, R-SIB1, SIBx, and/or R-SIBx overlap witheach other (e.g., when the MIB, SIB1, R-SIB1, SIBx, and/or R-SIBxoverlap or conflict in the time domain), if the R-UE needs to receiveall (or some) of the overlapping system information but the R-UE isincapable of receiving the overlapping system information at the sametime, the R-UE may receive selected information (e.g., including atleast one of the MIB, SIB1, SIBx, and/or R-SIBx) according to theconfigured priorities.

[Proposal #2] when Selecting an Initial Cell, the R-UE May Proceed witha Legacy Initial DL BWP Until Receiving at Least a PDCCH for SIB1 fromthe Serving Cell. After Receiving the PDCCH, the R-UE May Switch to anInitial DL R-BWP and Perform System Information, Paging, and RandomAccess Operations.

FIG. 11 illustrates an exemplary initial access process according toProposal #2.

For example, the R-UE may receive an MIB from a selected cell during aninitial cell selection process, a measurement process, and/or a mobilityprocess such as handover (C05).

The R-UE may check whether there is a CORESET for a Type0-PDCCH CSS,i.e., CORESET0, based on the received MIB. If the R-UE supports legacyCORESET0, legacy CORESET0 and a legacy Type0-PDCCH CSS may be defined asCORESET0 for the R-UE and a Type0-PDCCH CSS for the R-UE, respectively.The R-UE may receive a PDCCH in the legacy CSS (C10 and C15). Forexample, since the R-UE supports legacy CORESET0 and the legacy CSS, theR-UE may also monitor the PDCCH in the same way as in the prior art (C10and C15) (e.g., BWP switching to R-BWP at timing t2 in FIG. 12 ).

For example, when there is no CSS for the R-UE during the initial cellselection process, the measurement process, and/or the mobility processsuch as handover, the PBCH payload (e.g., pdcch-ConfigSIB1 or otherinformation in the MIB) may provide (i) information on a frequencylocation at which an SSB/SIB1 for the legacy UE or an SSB/R-SIB1 for theR-UE is expected; and/or (ii) information on a frequency range wherethere are no SSB/SIB1 for the legacy UE or no SSB/R-SIB1 for the R-UE.For example, the BS may indicate whether the provided information:information (i) and/or (ii) is for the legacy UE or for the R-UE, basedon the MIB (e.g., using reserved bits of the MIB). The BS may use theMIB (e.g., reserved bits of the MIB) to inform whether the R-UE needs tomeasure corresponding resources for cell reselection, mobility, or ANR.The R-UE may detect the frequency location of the SSB/R-SIB1 for theR-UE based on the provided information: information (i) and/or (ii).After receiving the MIB, the R-UE may determine CORESET0 and a PDCCHoccasion for the R-UE.

Based on the CSS, the R-UE may detect a DCI format with a CRC scrambledby a specific RNTI by monitoring a PDCCH for scheduling R-SIB1 during acorresponding period. In this case, the specific RNTI may be a legacySI-RNTI or an RNTI for receiving R-SIB1 dedicated to the R-UE. Duringthe PDCCH reception operation, the R-UE may determine that a legacyinitial DL BWP is activated and an initial DL R-BWP is deactivated. Inthis case, the DCI format is defined as a legacy DCI format (e.g., DCIof FIG. 12(b)) or a DCI format dedicated to the R-UE (e.g., R-DCI ofFIG. 12(a)/(b)).

At least some of the following information may be transmitted by the DCIformat for R-SIB1.

-   -   FDRA: Ceiling [log₂{N_(RB) ^(DL,BWP)(N_(RB) ^(DL,BWP)+1)/2}]        bits, where N_(RB) ^(DL,BWP) is defined by the size of CORESET0.    -   Information on CORESET0 only for the R-UE

1) Frequency-domain offset: The position of CORESET0 for the R-UErelative to the frequency position at which the PDCCH is transmitted maybe indicated by an offset. The corresponding frequency-domain offset maybe configured at the RB and/or RE level, and in this case, the RB leveloffset may vary for each frequency band. Alternatively, thefrequency-domain offset may be defined as an offset between the first orlast RB of an SSB/PBCH and the first RB of CORESET0 for the R-UE, or thefrequency-domain offset may be defined as an offset between the first orlast RB of legacy CORESET0 and the first or last RB of CORESET0 for theR-UE.

2) Time-domain offset: The symbols of CORESET0 for the R-UE relative tothe symbols in which the PDCCH is transmitted may be indicated by anoffset. The time-domain offset may be set to the number of symbols.Alternatively, CORESET0 for the R-UE may be configured to be locatedbefore or after the time-domain offset from an SSB/PBCH or legacyCORESET0.

-   -   TDRA (Time domain resource assignment)    -   VRB-to-PRB mapping    -   MCS (Modulation and coding scheme)    -   RV (Redundancy Version)    -   Aggregation factor: The aggregation factor indicates the number        of times that R-SIB1 is repeatedly transmitted (repetition        number).    -   SI indicator: The SI indicator indicates whether SIB1 is R-SIB1        or legacy SIB1 and/or whether SIBx is R-SIBx or legacy SIBx.    -   Reserved bit(s)

The UE may attempt to receive R-SIB1 over a PDSCH based on informationincluded in DCI (C20).

To this end, the UE may determine that the initial DL R-BWP associatedwith R-SIB1 transmission resources or the initial DL R-BWP determined inassociation with CORESET0 for the R-UE is activated, active, or valid.On the other hand, the R-UE may determine that the initial DL BWP forthe legacy UE is deactivated, inactive, or invalid.

For example, the contents of R-SIB1 may be the same as those describedin Proposal #1.

Alternatively, the R-UE may maintain both the initial DL BWP and theinitial DL R-BWP in the active state and switch between the two BWPs, sothat the R-UE may alternately receive the PDCCH in the initial DL BWPand R-SIB1 in the initial DL R-BWP. Upon receiving R-SIB1 in the activeinitial DL R-BWP, the UE may request or receive R-SIBx transmissiondedicated to the R-UE based on the scheduling information as in Proposal#1.

After switching to the initial DL R-BWP, the UE may monitor R-SIB1 inthe initial DL R-BWP based on CORESET0 information dedicated to the R-UEincluded in the DCI. As long as the R-UE receives CORESET0 dedicated tothe R-UE (e.g., as long as the R-UE receives a PDCCH scheduling R-SIB1),the R-UE does not need to switch to the legacy initial DL BWP formonitoring the PDCCH. Similarly as described in Proposal #1, if the CSSand CORESET0 for the R-UE are different from CORESET0 of the legacy UE,or if CORESET0 for the R-UE is out of the initial legacy DL BWP, the UEmay determine that the initial DL R-BWP determined in association withCORESET0 for the R-UE is activated, active, or valid. On the other hand,the UE may determine that the initial DL BWP is deactivated, inactive,or invalid.

Thereafter, the R-UE may receive an RAR (Msg2) or a contentionresolution message (Msg4) in the initial DL R-BWP in the random accessprocess. Then, the R-UE may receive a paging indicator or a pagingmessage.

Meanwhile, priorities may be given to an MIB, SIB1, R-SIB1, and/ordifferent (R-)SIBx. For example, the priorities may be configured byR-SIB1. When the MIB, SIB1, R-SIB1, SIBx, and/or R-SIBx overlap witheach other (e.g., when the MIB, SIB1, R-SIB1, SIBx, and/or R-SIBxoverlap or conflict in the time domain), if the R-UE needs to receiveall (or some) of the overlapping system information but the R-UE isincapable of receiving the overlapping system information at the sametime, the R-UE may receive selected information (e.g., including atleast one of the MIB, SIB1, SIBx, and/or R-SIBx) according to theconfigured priorities.

[Proposal #3] when Selecting an Initial Cell, the R-UE May Proceed witha Legacy Initial DL BWP Until Receiving at Least SIB1 from the ServingCell. After Receiving SIB1, the R-UE May Switch to an Initial DL R-BWPto Receive Additional R-SIB1 and Perform SIBx Reception, Paging, andRandom Access Operations.

For example, the R-UE may receive an MIB from a selected cell during aninitial cell selection process, a measurement process, and/or a mobilityprocess such as handover.

The R-UE may check whether there is a CORESET for a Type0-PDCCH CSS,i.e., CORESET0, based on the received MIB. When the R-UE supports legacyCORESET0, legacy CORESET0 and a legacy Type0-PDCCH CSS may be defined asCORESET0 for the R-UE and a Type0-PDCCH CSS for the R-UE, respectively.The R-UE may receive a PDCCH in the legacy CSS. For example, since theR-UE supports legacy CORESET0 and the legacy CSS, the R-UE may alsomonitor the PDCCH in the same way as in the prior art. Thereafter, theR-UE may receive SIB1 shared by the legacy UE and the R-UE based onlegacy DCI received over a legacy PDCCH (e.g., FIG. 14 ).

In this case, legacy SIB1 may include at least some of the followinginformation. After receiving legacy SIB1, the R-UE may receive R-SIB1 byswitching to the initial DL R-BWP based on this information (e.g., BWPswitching to R-BWP at timing t3 shown in FIG. 14 ). Here, the R-UE mayreceive DCI in the initial DL R-BWP to receive R-SIB1 (e.g., FIG.14(a)), or the R-UE may receive R-SIB1 without receiving DCI (e.g., FIG.14(b)).

-   -   FDRA: Ceiling [log₂{N_(RB) ^(DL,BWP)(N_(RB) ^(DL,BWP)+1)/2}]        bits, where N_(RB) ^(DL,BWP) is defined by the size of CORESET0.    -   Information on CORESET0 only for the R-UE

1) Frequency-domain offset: The position of CORESET0 for the R-UErelative to the frequency position at which the PDCCH is transmitted maybe indicated by an offset. The corresponding frequency-domain offset maybe configured at the RB and/or RE level, and in this case, the RB leveloffset may vary for each frequency band. Alternatively, thefrequency-domain offset may be defined as an offset between the first orlast RB of an SSB/PBCH and the first RB of CORESET0 for the R-UE, or thefrequency-domain offset may be defined as an offset between the first orlast RB of legacy CORESET0 and the first or last RB of CORESET0 for theR-UE.

2) Time-domain offset: The symbols of CORESET0 for the R-UE may beindicated by an offset, compared to the symbols in which the PDCCH istransmitted. The time-domain offset may be set to the number of symbols.Alternatively, CORESET0 for the R-UE may be configured to be locatedbefore or after the time-domain offset from an SSB/PBCH or legacyCORESET0.

-   -   TDRA (Time domain resource assignment)    -   VRB-to-PRB mapping    -   MCS (Modulation and coding scheme)    -   RV (Redundancy Version)    -   Aggregation factor: The aggregation factor indicates the number        of times that R-SIB1 is repeatedly transmitted (repetition        number).

The R-UE may additionally receive DCI for receiving R-SIB1 similarly asdescribed in Proposal #2 (e.g., FIG. 14(a)). After receiving legacySIB1, the UE may switch to the initial DL R-BWP (e.g., BWP switching toR-BWP at timing t3 shown in FIG. 14(a)) and receive R-SIB1 based on theadditional DCI. Alternatively, the R-UE may receive R-SIB1 transmissioninformation such as the DCI format of Proposal #2 with reserved bits ofthe legacy DCI (e.g., DCI for scheduling SIB1). Accordingly, the R-UEmay receive R-SIB1 by switching to the initial DL R-BWP with noadditional DCI reception (e.g., BWP switching to R-BWP at timing t3 inFIG. 15 ).

To this end, the UE may determine that the initial DL R-BWP associatedwith R-SIB1 transmission resources is activated, active, or valid. Onthe other hand, the R-UE may determine that the initial DL BWP for thelegacy UE is deactivated, inactive, or invalid. Alternatively, the R-UEmay maintain both the initial DL BWP and the initial DL R-BWP in theactive state and switch between the two BWPs, so that the R-UE mayalternately receive the two SIB1s.

For the R-UE, legacy SIB1 or R-SIB1 may include some or all of thefollowing information. In particular, at least some of the followinginformation may be included.

-   -   Scheduling Information: Information on whether SIBx shared by        the legacy UE and R-UE is broadcast or a transmission period        thereof, or information on whether R-SIBx dedicated to the R-UE        is broadcast or a transmission period thereof    -   RACH Configuration Information: RACH configuration information        shared by the legacy UE and R-UE or RACH configuration        information dedicated to the R-UE    -   Initial UL BWP Information: Initial UL BWP configuration        information shared by the legacy UE and R-UE or initial UL BWP        configuration information dedicated to the R-UE    -   Access Control Information (Access Control Parameters):        Probability-based access control information shared by the        legacy UE and R-UE or probability-based access control        information dedicated to the R-UE. When there are multiple types        of R-UEs, the access control information may carry a different        parameter value for each type of R-UE. The R-UE may determine        whether UL transmission for initial access is allowed based on        probability, using parameter values (e.g., barring factor and        barring time) corresponding to the type of the R-UE.

For example, scheduling information for legacy SIBx and initial UL BWPinformation may be included and transmitted in legacy SIB1, andscheduling information for R-SIBx, initial UL R-BPW information, RACHconfiguration information, and access control information, which arededicated to the R-UE, may be included and transmitted in R-SIB1.

Thereafter, the UE may request or receive transmission of R-SIBx basedon the scheduling information in R-SIB1. The R-UE may receive an RAR ora contention resolution message in the initial DL R-BWP in the randomaccess process. Then, the R-UE may receive a paging indicator or apaging message.

Meanwhile, priorities may be given to an MIB, SIB1, R-SIB1, and/ordifferent (R-)SIBx. The priorities may be configured by SIB1 or R-SIB1.When the MIB, SIB1, R-SIB1, SIBx, and/or R-SIBx overlap with each other(e.g., when the MIB, SIB1, R-SIB1, SIBx, and/or R-SIBx overlap orconflict in the time domain), if the R-UE needs to receive all (or some)of the overlapping system information but the R-UE is incapable ofreceiving the overlapping system information at the same time, the R-UEmay receive selected information (e.g., including at least one of theMIB, SIB1, SIBx, and/or R-SIBx) according to the configured priorities.

[Proposal #4] when Selecting an Initial Cell, the R-UE May Proceed witha Legacy Initial DL BWP Until Receiving at Least SIB1 from the ServingCell. After Receiving SIB1, the R-UE May Switch to an Initial DL R-BWPand Perform SIBx Reception, Paging, and Random Access Operations.

For example, the R-UE may receive an MIB from a selected cell during aninitial cell selection process, a measurement process, and/or a mobilityprocess such as handover.

The R-UE may check whether there is a CORESET for a Type0-PDCCH CSS,i.e., CORESET0, based on the received MIB. When the R-UE supports legacyCORESET0, legacy CORESET0 and a legacy Type0-PDCCH CSS may be defined asCORESET0 for the R-UE and a Type0-PDCCH CSS for the R-UE, respectively.The R-UE may receive a PDCCH in the legacy CSS. For example, since theR-UE supports legacy CORESET0 and the legacy CSS, the R-UE may alsomonitor the PDCCH in the same way as in the prior art. Thereafter, theR-UE may receive SIB1 shared by the legacy UE and the R-UE based onlegacy DCI received over a legacy PDCCH. In this case, the contents ofSIB1 may be the same as those described in Proposal #1. (e.g., FIG. 16).

The UE may request or receive transmission of R-SIBx based on schedulinginformation in R-SIB1 (e.g., BWP switching to R-BWP at timing t3 in FIG.16 ). To this end, the R-UE may determine that the initial DL R-BWPassociated with R-SIBx transmission resources is activated, active, orvalid. On the other hand, the R-UE may determine that the initial DL BWPfor the legacy UE is deactivated, inactive, or invalid. Alternatively,the R-UE may maintain both the initial DL BWP and the initial DL R-BWPin the active state and switch between the two BWPs, so that the R-UEmay periodically receive both SIB1 and R-SIBx in different timedurations.

The R-UE may receive an RAR or a contention resolution message in theinitial DL R-BWP in the random access process. Then, the R-UE mayreceive a paging indicator or a paging message.

Meanwhile, priorities may be given to an MIB, SIB1 and/or different(R-)SIBx. The priorities may be configured by SIB1. When the MIB, SIB1,SIBx and/or R-SIBx overlap (e.g., when the MIB, SIB1, SIBx and/or R-SIBxoverlap or conflict in the time domain), if the R-UE needs to receiveall (or some) of the overlapping system information but the R-UE isincapable of receiving the overlapping system information at the sametime, the R-UE may receive selected information (e.g., including atleast one of the MIB, SIB1, SIBx, and/or R-SIBx) according to theconfigured priorities.

According to the above-mentioned proposals, the initial DL R-BWPdedicated to the R-UE may be efficiently provided. Accordingly, the R-UEsupporting limited UE capability compared to legacy UEs may successfullyperform the cell access process and coexist with the legacy UEs.

FIG. 17 illustrates an exemplary signal transmission/reception methodbased on the above-mentioned proposals. FIG. 17 is one of examples towhich present disclosure is applicable, and the present disclosure isnot limited to the example of FIG. 17 . The above-described details maybe referred to for illustration of FIG. 17 even if not explicitlystated.

ABS may transmit a PBCH signal in an SSB on a first DL BWP (e.g., BWP1of FIG. 17 ) (D05). A UE may detect the PBCH signal in the SSB on thefirst DL BWP. The UE may obtain partial system information including anMIB carried by the PBCH signal from among first system informationprovided on the first DL BWP (D10).

The BS may transmit second system information on a second DL BWPdifferent from the first DL BWP (D20). The BS may support a first typeof UE (e.g., Rel. 15/16 NR UE) and a second type of UE (e.g., Rel.17+RedCap UE) with reduced capability to support a smaller bandwidththan the first type of UE. The BS may provide the second type of UE withthe partial system information including the MIB carried by the PBCHsignal by transmitting the first system information on the first DL BWP.The BS may provide the second type of UE with remaining systeminformation by transmitting the second system information on the secondDL BWP.

Based that the UE is the second type of UE with the reduced capabilityto support the smaller bandwidth than the first type of UE, the UE mayperform BWP switching from the first DL BWP to the second DL BWP (D15).The UE may obtain the second system information provided on the secondDL BWP as remaining parts except for the partial system informationobtained on the first DL BWP (D25).

The UE may perform cell access based on a plurality of initial DL BWPs.

The first DL BWP and the second DL BWP may be a first initial DL BWP anda second initial DL BWP, respectively.

The first DL BWP may be related to a bandwidth of the first type of UE,and the second DL BWP may be related to a bandwidth of the second typeof UE.

The PBCH signal on the first DL BWP may be a common signal for the firsttype of UE and the second type of UE.

The second system information may be information for the second type ofUE other than the first type of UE. The second system information mayinclude at least one second-type SIB for the second type of UE.

Obtaining, by the UE, the partial system information on the first DL BWPmay include: obtaining a first CORESET configuration and a first CSSconfiguration from the MIB, wherein the first CORESET configuration andthe first CSS configuration are related to control informationscheduling first-type SIB1 for the first type of UE; and obtaining thefirst-type SIB1 based on the first CORESET configuration and the firstCSS configuration.

Obtaining, by the UE, the second system information on the second DL BWPmay include obtaining at least one second-type SIB provided on thesecond DL BWP based on the first-type SIB1.

Obtaining, by the UE, the partial system information on the first DL BWPmay include obtaining a first CORESET configuration and a first CSSconfiguration from the MIB, wherein the first CORESET configuration andthe first CSS configuration are related to control informationscheduling first-type SIB1 for the first type of UE.

Obtaining, by the UE, the second system information on the second DL BWPmay include: —obtaining at least one of a second CORESET configurationor a second CSS configuration on the second DL BWP by applying atime/frequency offset to at least one of the first CORESET configurationor the first CSS configuration; and obtaining at least one second-typeSIB provided on the second DL BWP based on the at least one of thesecond CORESET configuration or the second CSS configuration.

FIG. 18 illustrates a communication system 1 applied to the presentdisclosure.

Referring to FIG. 18 , a communication system 1 includes wirelessdevices, Base Stations (BSs), and a network. Herein, the wirelessdevices represent devices performing communication using Radio AccessTechnology (RAT) (e.g., 5G New RAT (NR)) or Long-Term Evolution (LTE))and may be referred to as communication/radio/5G devices. The wirelessdevices may include, without being limited to, a robot 100 a, vehicles100 b-1 and 100 b-2, an eXtended Reality (XR) device 100 c, a hand-helddevice 100 d, a home appliance 100 e, an Internet of Things (IoT) device100 f, and an Artificial Intelligence (AI) device/server 400. Forexample, the vehicles may include a vehicle having a wirelesscommunication function, an autonomous driving vehicle, and a vehiclecapable of performing communication between vehicles. Herein, thevehicles may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone).The XR device may include an Augmented Reality (AR)/Virtual Reality(VR)/Mixed Reality (MR) device and may be implemented in the form of aHead-Mounted Device (HMD), a Head-Up Display (HUD) mounted in a vehicle,a television, a smartphone, a computer, a wearable device, a homeappliance device, a digital signage, a vehicle, a robot, etc. Thehand-held device may include a smartphone, a smartpad, a wearable device(e.g., a smartwatch or a smartglasses), and a computer (e.g., anotebook). The home appliance may include a TV, a refrigerator, and awashing machine. The IoT device may include a sensor and a smartmeter.For example, the BSs and the network may be implemented as wirelessdevices and a specific wireless device 200 a may operate as a BS/networknode with respect to other wireless devices.

The wireless devices 100 a to 100 f may be connected to the network 300via the BSs 200. An AI technology may be applied to the wireless devices100 a to 100 f and the wireless devices 100 a to 100 f may be connectedto the AI server 400 via the network 300. The network 300 may beconfigured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g.,NR) network. Although the wireless devices 100 a to 100 f maycommunicate with each other through the BSs 200/network 300, thewireless devices 100 a to 100 f may perform direct communication (e.g.,sidelink communication) with each other without passing through theBSs/network. For example, the vehicles 100 b-1 and 100 b-2 may performdirect communication (e.g. Vehicle-to-Vehicle(V2V)/Vehicle-to-everything (V2X) communication). The IoT device (e.g.,a sensor) may perform direct communication with other IoT devices (e.g.,sensors) or other wireless devices 100 a to 100 f.

Wireless communication/connections 150 a, 150 b, or 150 c may beestablished between the wireless devices 100 a to 100 f/BS 200, or BS200/BS 200. Herein, the wireless communication/connections may beestablished through various RATs (e.g., 5G NR) such as uplink/downlinkcommunication 150 a, sidelink communication 150 b (or, D2Dcommunication), or inter BS communication (e.g. relay, Integrated AccessBackhaul (IAB)). The wireless devices and the BSs/the wireless devicesmay transmit/receive radio signals to/from each other through thewireless communication/connections 150 a and 150 b. For example, thewireless communication/connections 150 a and 150 b may transmit/receivesignals through various physical channels. To this end, at least a partof various configuration information configuring processes, varioussignal processing processes (e.g., channel encoding/decoding,modulation/demodulation, and resource mapping/demapping), and resourceallocating processes, for transmitting/receiving radio signals, may beperformed based on the various proposals of the present disclosure.

FIG. 19 illustrates wireless devices applicable to the presentdisclosure.

Referring to FIG. 19 , a first wireless device 100 and a second wirelessdevice 200 may transmit radio signals through a variety of RATs (e.g.,LTE and NR). Herein, {the first wireless device 100 and the secondwireless device 200} may correspond to {the wireless device 100 x andthe BS 200} and/or {the wireless device 100 x and the wireless device100 x} of FIG. 18 .

The first wireless device 100 may include one or more processors 102 andone or more memories 104 and additionally further include one or moretransceivers 106 and/or one or more antennas 108. The processor(s) 102may control the memory(s) 104 and/or the transceiver(s) 106 and may beconfigured to implement the descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument. For example, the processor(s) 102 may process informationwithin the memory(s) 104 to generate first information/signals and thentransmit radio signals including the first information/signals throughthe transceiver(s) 106. The processor(s) 102 may receive radio signalsincluding second information/signals through the transceiver 106 andthen store information obtained by processing the secondinformation/signals in the memory(s) 104. The memory(s) 104 may beconnected to the processor(s) 102 and may store a variety of informationrelated to operations of the processor(s) 102. For example, thememory(s) 104 may store software code including commands for performinga part or the entirety of processes controlled by the processor(s) 102or for performing the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.Herein, the processor(s) 102 and the memory(s) 104 may be a part of acommunication modem/circuit/chip designed to implement RAT (e.g., LTE orNR). The transceiver(s) 106 may be connected to the processor(s) 102 andtransmit and/or receive radio signals through one or more antennas 108.Each of the transceiver(s) 106 may include a transmitter and/or areceiver. The transceiver(s) 106 may be interchangeably used with RadioFrequency (RF) unit(s). In the present disclosure, the wireless devicemay represent a communication modem/circuit/chip.

The second wireless device 200 may include one or more processors 202and one or more memories 204 and additionally further include one ormore transceivers 206 and/or one or more antennas 208. The processor(s)202 may control the memory(s) 204 and/or the transceiver(s) 206 and maybe configured to implement the descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument. For example, the processor(s) 202 may process informationwithin the memory(s) 204 to generate third information/signals and thentransmit radio signals including the third information/signals throughthe transceiver(s) 206. The processor(s) 202 may receive radio signalsincluding fourth information/signals through the transceiver(s) 106 andthen store information obtained by processing the fourthinformation/signals in the memory(s) 204. The memory(s) 204 may beconnected to the processor(s) 202 and may store a variety of informationrelated to operations of the processor(s) 202. For example, thememory(s) 204 may store software code including commands for performinga part or the entirety of processes controlled by the processor(s) 202or for performing the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.Herein, the processor(s) 202 and the memory(s) 204 may be a part of acommunication modem/circuit/chip designed to implement RAT (e.g., LTE orNR). The transceiver(s) 206 may be connected to the processor(s) 202 andtransmit and/or receive radio signals through one or more antennas 208.Each of the transceiver(s) 206 may include a transmitter and/or areceiver. The transceiver(s) 206 may be interchangeably used with RFunit(s). In the present disclosure, the wireless device may represent acommunication modem/circuit/chip.

Hereinafter, hardware elements of the wireless devices 100 and 200 willbe described more specifically. One or more protocol layers may beimplemented by, without being limited to, one or more processors 102 and202. For example, the one or more processors 102 and 202 may implementone or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP,RRC, and SDAP). The one or more processors 102 and 202 may generate oneor more Protocol Data Units (PDUs) and/or one or more Service Data Unit(SDUs) according to the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document. Theone or more processors 102 and 202 may generate messages, controlinformation, data, or information according to the descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document. The one or more processors 102 and 202 maygenerate signals (e.g., baseband signals) including PDUs, SDUs,messages, control information, data, or information according to thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document and provide thegenerated signals to the one or more transceivers 106 and 206. The oneor more processors 102 and 202 may receive the signals (e.g., basebandsignals) from the one or more transceivers 106 and 206 and acquire thePDUs, SDUs, messages, control information, data, or informationaccording to the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.

The one or more processors 102 and 202 may be referred to ascontrollers, microcontrollers, microprocessors, or microcomputers. Theone or more processors 102 and 202 may be implemented by hardware,firmware, software, or a combination thereof. As an example, one or moreApplication Specific Integrated Circuits (ASICs), one or more DigitalSignal Processors (DSPs), one or more Digital Signal Processing Devices(DSPDs), one or more Programmable Logic Devices (PLDs), or one or moreField Programmable Gate Arrays (FPGAs) may be included in the one ormore processors 102 and 202. The descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument may be implemented using firmware or software and the firmwareor software may be configured to include the modules, procedures, orfunctions. Firmware or software configured to perform the descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document may be included in the one or more processors102 and 202 or stored in the one or more memories 104 and 204 so as tobe driven by the one or more processors 102 and 202. The descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document may be implemented using firmware or softwarein the form of code, commands, and/or a set of commands.

The one or more memories 104 and 204 may be connected to the one or moreprocessors 102 and 202 and store various types of data, signals,messages, information, programs, code, instructions, and/or commands.The one or more memories 104 and 204 may be configured by Read-OnlyMemories (ROMs), Random Access Memories (RAMs), Electrically ErasableProgrammable Read-Only Memories (EPROMs), flash memories, hard drives,registers, cash memories, computer-readable storage media, and/orcombinations thereof. The one or more memories 104 and 204 may belocated at the interior and/or exterior of the one or more processors102 and 202. The one or more memories 104 and 204 may be connected tothe one or more processors 102 and 202 through various technologies suchas wired or wireless connection.

The one or more transceivers 106 and 206 may transmit user data, controlinformation, and/or radio signals/channels, mentioned in the methodsand/or operational flowcharts of this document, to one or more otherdevices. The one or more transceivers 106 and 206 may receive user data,control information, and/or radio signals/channels, mentioned in thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document, from one or moreother devices. For example, the one or more transceivers 106 and 206 maybe connected to the one or more processors 102 and 202 and transmit andreceive radio signals. For example, the one or more processors 102 and202 may perform control so that the one or more transceivers 106 and 206may transmit user data, control information, or radio signals to one ormore other devices. The one or more processors 102 and 202 may performcontrol so that the one or more transceivers 106 and 206 may receiveuser data, control information, or radio signals from one or more otherdevices. The one or more transceivers 106 and 206 may be connected tothe one or more antennas 108 and 208 and the one or more transceivers106 and 206 may be configured to transmit and receive user data, controlinformation, and/or radio signals/channels, mentioned in thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document, through the one ormore antennas 108 and 208. In this document, the one or more antennasmay be a plurality of physical antennas or a plurality of logicalantennas (e.g., antenna ports). The one or more transceivers 106 and 206may convert received radio signals/channels etc. from RF band signalsinto baseband signals in order to process received user data, controlinformation, radio signals/channels, etc. using the one or moreprocessors 102 and 202. The one or more transceivers 106 and 206 mayconvert the user data, control information, radio signals/channels, etc.processed using the one or more processors 102 and 202 from the baseband signals into the RF band signals. To this end, the one or moretransceivers 106 and 206 may include (analog) oscillators and/orfilters.

FIG. 20 is a diagram illustrating a DRX operation of a UE according toan embodiment of the present disclosure.

The UE may perform a DRX operation in the afore-described/proposedprocedures and/or methods. A UE configured with DRX may reduce powerconsumption by receiving a DL signal discontinuously. DRX may beperformed in an RRC_IDLE state, an RRC_INACTIVE state, and anRRC_CONNECTED state. The UE performs DRX to receive a paging signaldiscontinuously in the RRC_IDLE state and the RRC_INACTIVE state. DRX inthe RRC_CONNECTED state (RRC_CONNECTED DRX) will be described below.

A DRX cycle includes an On Duration and an Opportunity for DRX. The DRXcycle defines a time interval between periodic repetitions of the OnDuration. The On Duration is a time period during which the UE monitorsa PDCCH. When the UE is configured with DRX, the UE performs PDCCHmonitoring during the On Duration. When the UE successfully detects aPDCCH during the PDCCH monitoring, the UE starts an inactivity timer andis kept awake. On the contrary, when the UE fails in detecting any PDCCHduring the PDCCH monitoring, the UE transitions to a sleep state afterthe On Duration. Accordingly, when DRX is configured, PDCCHmonitoring/reception may be performed discontinuously in the time domainin the afore-described/proposed procedures and/or methods. For example,when DRX is configured, PDCCH reception occasions (e.g., slots withPDCCH SSs) may be configured discontinuously according to a DRXconfiguration in the present disclosure. On the contrary, when DRX isnot configured, PDCCH monitoring/reception may be performed continuouslyin the time domain. For example, when DRX is not configured, PDCCHreception occasions (e.g., slots with PDCCH SSs) may be configuredcontinuously in the present disclosure. Irrespective of whether DRX isconfigured, PDCCH monitoring may be restricted during a time periodconfigured as a measurement gap.

The above-described embodiments are combinations of elements andfeatures of the present disclosure in specific forms. The elements orfeatures may be considered selective unless mentioned otherwise. Eachelement or feature may be implemented without being combined with otherelements or features. Further, the embodiments of the present disclosuremay be configured by combining some elements and/or some features.Operation orders described in the embodiments of the present disclosuremay be rearranged. Some constructions or features of any one embodimentmay be included in another embodiment or may be replaced withcorresponding constructions or features of another embodiment. It isobvious that claims that are not explicitly cited in the appended claimsmay be presented in combination as an embodiment of the presentdisclosure or included as a new claim by subsequent amendment after theapplication is filed.

Those skilled in the art will appreciate that the present disclosure maybe carried out in other specific ways than those set forth hereinwithout departing from the spirit and essential characteristics of thepresent disclosure. The above embodiments are therefore to be construedin all aspects as illustrative and not restrictive. The scope of thedisclosure should be determined by the appended claims and their legalequivalents, not by the above description, and all changes coming withinthe meaning and equivalency range of the appended claims are intended tobe embraced therein.

INDUSTRIAL APPLICABILITY

The present disclosure is applicable to UEs, BSs, or other apparatusesin a wireless mobile communication system.

1. A method of receiving a signal by a user equipment (UE) in a wirelesscommunication system, the method comprising: detecting a physicalbroadcast channel (PBCH) signal through a synchronization signal block(SSB) on a first downlink (DL) bandwidth part (BWP); and obtaining firstsystem information based on the PBCH signal on the first DL BWP,wherein, based on i) that the UE is a second type UE having a reducedcapability than a first type UE, and ii) that a second DL BWP dedicatedto the second type UE different from the first DL BWP is present, the UEassumes that the second DL BWP provides second system information otherthan the first system information and operates on the second DL BWP. 2.The method of claim 1, wherein the second DL BWP is an initial DL BWPdedicated to the second type UE.
 3. The method of claim 1, wherein thesecond DL BWP does not exceed a maximum bandwidth of the second type UE.4. The method of claim 1, wherein the PBCH signal on the first DL BWP isa common signal for the first type of UE and the second type of UE. 5.The method of claim 1, wherein the second system information isinformation for the second type of UE other than the first type of UE.6. The method of claim 5, wherein the second system information includesat least one second-type system information block (SIB) for the secondtype of UE.
 7. The method of claim 1, wherein obtaining the first systeminformation on the first DL BWP comprises: obtaining a first controlresource set (CORESET) configuration and a first common search space(CSS) configuration from the MIB which are related to controlinformation scheduling system information block 1 (SIB1); and obtainingthe SIB1 based on the first CORESET configuration and the first CSSconfiguration.
 8. The method of claim 2, wherein the UE obtains, basedon the first system information obtained on the first DL BWP,information regarding the second DL BWP which is the initial DL BWPdedicated to the second type UE.
 9. A processor-readable storage mediumhaving stored thereon a program for executing the method of claim
 1. 10.A device for wireless communication, the device comprising: a memoryconfigured to store instructions; and a processor configured to performoperations by executing the instructions, wherein the operationsperformed by the processor comprise: detecting a physical broadcastchannel (PBCH) signal through a synchronization signal block (SSB) on afirst downlink (DL) bandwidth part (BWP); and obtaining first systeminformation based on the PBCH signal on the first DL BWP, wherein, basedon i) that the device is a second type device having a reducedcapability than a first type device, and ii) that a second DL BWPdedicated to the second type device different from the first DL BWP ispresent, the processor assumes that the second DL BWP provides secondsystem information other than the first system information and operateson the second DL BWP.
 11. The device of claim 10, further comprising atransceiver configured to transmit and receive a radio signal undercontrol of the processor, wherein the device is a user equipment (UE)for 3rd generation partnership project (3GPP) based wirelesscommunication.
 12. The device of claim 10, wherein the device is anapplication-specific integrated circuit (ASIC) or a digital signalprocessing device.
 13. A method of transmitting a signal by a basestation in a wireless communication system, the method comprising:transmitting first system information including a physical broadcastchannel (PBCH) signal through a synchronization signal block (SSB) on afirst downlink (DL) bandwidth part (BWP); and transmitting second systeminformation other than the first system information on a second DL BWPdifferent from the first DL BWP, wherein the base station is configuredto: support both a first type of UE and a second type of UE having areduced capability than the first type UE; and configure the second DLBWP as an initial DL BWP dedicated to the second type UE.
 14. A basestation configured to transmit a signal in a wireless communicationsystem, the base station comprising: a memory configured to storeinstructions; and a processor configured to perform operations byexecuting the instructions, wherein the operations performed by theprocessor comprise: transmitting first system information including aphysical broadcast channel (PBCH) signal in a synchronization signalblock (SSB) on a first downlink (DL) bandwidth part (BWP); andtransmitting second system information other than the first systeminformation on a second DL BWP different from the first DL BWP, andwherein the processor is configured to: support both a first type of UEand a second type of UE having a reduced capability than the first typeUE; and configure the second DL BWP as an initial DL BWP dedicated tothe second type UE.